The present invention relates generally to electrical machines and more particularly to a cooling structure for use with electrical machines.
Higher temperatures in electrical machines can be the source of performance degradation, decrease in power density, and reduction in reliability for the machine. Thermal “hot spots” may be a specific manifestation of this issue. Within the stator assembly and at or near the end windings, in particular, is often the hottest portion of the stator. Effective extraction of heat in these areas can be difficult.
Copper losses, often the most significant losses in an electrical machine, are generated by the winding conductors located in winding slots within the lamination stack of the machine. Heat generated, due to ohmic losses within the conductors, has to travel through insulation layers (e.g., ground wall, phase separators, conductor coating, VPI resin, etc.). Due to the poor thermal conductivity of the various insulation layers, the conductors within the winding slots are often among the hottest parts of the electrical machine.
Accordingly, there is an ongoing need for improving upon thermal management in electrical machines.